Now might be a good time to tackle one of the quintessential exercise issues faced by most people. You, like many of your peers, want a six-pack rectus abdominis. Each day, you perform hundreds of twists, crunches, or sit-ups, but that desired definition just never becomes apparent. You can feel the muscles under your skin and you might even be quite lean, but those muscles of obsession are just not prominent.What could be the problem?More than likely, it has to do with your programming. It probably lacks intensity. Compare the physiques of a bodybuilder, a distance runner, and a sprinter. Of these three, which has the most prominent musculature?Low speed activity with bodyweight begets no rip.High speed activity with bodyweight improves the amount of rip.Weighted exercise maximises rip.The problem with your abdominal musculature is that you’re training them for a marathon when you should probably be training them to be strong and large. The endless bodyweight repetitions of sit-ups and crunches that most people believer will yield a six-pack will only provide muscular endurance. Why on earth would you decide to train the rest of your body in a weighted environment and endurance-train your core? It’s ludicrous. To correct the issue, you need only make a few modifications to what are probably doing in any case.First and foremost, add resistance. The rectus abdominis is a muscle. What do we do if we desire a larger and more defined chest? Perform a tonne of press-ups? Unlikely. No, it would be more prudent to add weight progressively to the bench press for that purpose and work up from that. To add the weight here, grab a plate and place it over your shoulders with your arms extended and perform a full sit-up. Secondly, we keep the repetitions between 10 and 12 for a couple of sets. You can build-up those abdominal muscles you want, but you have to be willing to put in the required effort. BibliographyKilgore, Lon. Anatomy without a scalpel. Iowa Park, Tex.: Killustrated Books, 2010. Kilgore, Lon, and Michael Hartman. Fit. Iowa Park, Tex.: Killustrated Books, 2011.